I just added a litle bit of grine and djust color curves a little bit.

here's the final coloring. maybe I'll add some grain in the final image and adjust the color balance.

the image is almost ready. as you can see I added lights and shines in those squid tentacles.

here I finish the shadow tones, as you can notice I already smudge the robot in the background.
next step will be the lights.

this is the color basic plasters. I also changed the color of the lineart to dark red. later on when all shadows are ready I'll mix it with the colors. with the smudge tool in photoshop.

here's the line art. I redraw everithing to fit the format I wanted and added some lement in the background to make it more interesting.

here's my pencil sketch, really sketchy